Earth's Internal Structure

Active learning works because the movement of tectonic plates is not something students can observe directly, so hands-on models and collaborative tasks make abstract processes concrete. Students build spatial reasoning when they manipulate materials to simulate plate interactions, which helps them visualize why the Earth’s surface changes over time.

• Year 7
• Geography
• 3 activities
• 40 min–50 min

Learning Objectives

1. Compare the physical properties (density, state, temperature) of the Earth's crust, mantle, and core.
2. Explain the primary sources of Earth's internal heat and how they drive convection currents.
3. Analyze seismic wave data to infer the composition and state of Earth's internal layers.
4. Identify the main chemical compositions of the Earth's crust, mantle, and core.

Simulation Game

⏱ 45 min·Pairs

Simulation Game: The Snack Tectonics Lab

Using biscuits to represent the crust and jam or cream to represent the mantle, students simulate different plate boundaries. They pull the biscuits apart (constructive), push them together (destructive), and slide them past each other (conservative). They must record the 'landforms' created by each movement.

Prepare & details

Explain the scientific evidence used to infer Earth's internal structure.

Facilitation Tip: During the Snack Tectonics Lab, circulate to ensure students gently pull the graham crackers apart to model divergent boundaries rather than scraping them noisily.

Setup: Flexible space for group stations

Materials: Role cards with goals/resources, Game currency or tokens, Round tracker

• Apply
• Analyze
• Evaluate
• Create
• Social Awareness
• Decision-Making

Inquiry Circle

⏱ 40 min·Small Groups

Inquiry Circle: Evidence for Pangaea

Groups are given a 'jigsaw' of the current continents but with added clues like matching fossil types and mountain ranges. They must work together to reconstruct the supercontinent of Pangaea, explaining their reasoning based on the evidence provided. This mirrors the work of early geologists like Alfred Wegener.

Prepare & details

Compare the properties of the Earth's crust, mantle, and core.

Facilitation Tip: When students investigate Pangaea evidence, ask guiding questions such as, 'How does this fossil distribution support Wegener’s idea?' to keep discussions focused.

Setup: Groups at tables with access to source materials

Materials: Source material collection, Inquiry cycle worksheet, Question generation protocol, Findings presentation template

• Analyze
• Evaluate
• Create
• Self-Management
• Self-Awareness

Peer Teaching

⏱ 50 min·Small Groups

Peer Teaching: Boundary Experts

The class is split into three groups: Constructive, Destructive, and Conservative experts. Each group creates a 2-minute 'news report' explaining what happens at their boundary, what landforms are created, and where in the world it can be found. They then present to the rest of the class.

Prepare & details

Analyze how the Earth's internal heat drives geological processes.

Facilitation Tip: For Boundary Experts, assign each student a role like 'convection researcher' or 'earthquake recorder' to ensure accountability during peer teaching.

Setup: Presentation area at front, or multiple teaching stations

Materials: Topic assignment cards, Lesson planning template, Peer feedback form, Visual aid supplies

• Understand
• Apply
• Analyze
• Create
• Self-Management
• Relationship Skills

Teaching This Topic

Teachers should approach this topic by starting with what students can see—maps and fossils—before moving to invisible forces like convection. Avoid rushing to diagrams of the Earth’s layers; instead, let students discover the relationship between heat, pressure, and plate movement through guided inquiry. Research shows that students grasp tectonic processes better when they experience the 'slow, sticky flow' of the mantle before labeling its parts.

What to Expect

Successful learning looks like students using evidence to explain continental drift, describing how heat in the mantle drives plate movement, and correcting misconceptions through experiments and peer discussion. By the end, they should confidently connect Earth’s internal heat to surface features like mountains and volcanoes.

Watch Out for These Misconceptions

Common Misconception

During the Snack Tectonics Lab, watch for students who describe the mantle as a 'pool of lava.'

What to Teach Instead

Use the silly putty demonstration before the lab to show how a solid can flow slowly. Ask students to stretch the putty and observe its behavior, then relate this to the mantle’s plastic-like flow driving plate movement.

Common Misconception

During the Boundary Experts peer teaching, listen for students who say plates only move during earthquakes.

What to Teach Instead

Set up a simple friction experiment with sandpaper during the peer teaching prep. Have students slowly pull two pieces of sandpaper past each other to show constant, gradual motion with occasional jerky stops and starts, mirroring real plate movement.

Assessment Ideas

Quick Check

After the Snack Tectonics Lab, provide a diagram of Earth’s internal layers. Ask students to label the crust, mantle, outer core, and inner core, and write one characteristic for each layer.

Discussion Prompt

During the Boundary Experts peer teaching, pose the question, 'What would happen if the mantle cooled down completely?' Facilitate a discussion about how convection currents rely on heat transfer.

Exit Ticket

After the Evidence for Pangaea activity, ask students to write down two pieces of evidence for continental drift and one way internal heat influences surface geology, such as volcanoes or mountain ranges.

Extensions & Scaffolding

• Challenge early finishers to predict how plate boundaries might change in the next 50 million years using their Snack Tectonics models.
• Scaffolding for struggling students: Provide pre-labeled diagrams of plate boundaries to annotate during the Evidence for Pangaea activity.
• Deeper exploration: Have students research how scientists use seismic waves to map the Earth’s interior, then present findings to the class.

Key Vocabulary

Lithosphere	The rigid outer part of the Earth, consisting of the crust and upper mantle, which is broken into tectonic plates.
Asthenosphere	The highly viscous, mechanically weak and ductile region of the upper mantle of Earth, directly below the lithosphere.
Convection Currents	The movement of heat energy through fluids (like the semi-molten rock in the mantle) by the circulation of currents, which are heated from below and cooled from above.
Seismic Waves	Waves of energy that travel through Earth's layers, generated by earthquakes or explosions, which provide data about the planet's interior.
Mohorovičić Discontinuity	The boundary between the Earth's crust and the mantle, identified by a change in seismic wave velocity.